[PATCH 2/6] MIPS/alchemy: factor out the DMA coherent setup

From: Christoph Hellwig
Date: Wed Feb 10 2021 - 05:02:35 EST


Factor out a alchemy_dma_coherent helper that determines if the platform
is DMA coherent. Also stop initializing the hw_coherentio variable, given
that is only ever set to a non-zero value by the malta setup code.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/mips/alchemy/common/setup.c | 33 ++++++++++++++++++--------------
1 file changed, 19 insertions(+), 14 deletions(-)

diff --git a/arch/mips/alchemy/common/setup.c b/arch/mips/alchemy/common/setup.c
index 0f60efe0481ecc..c2da68e7984450 100644
--- a/arch/mips/alchemy/common/setup.c
+++ b/arch/mips/alchemy/common/setup.c
@@ -37,6 +37,23 @@
extern void __init board_setup(void);
extern void __init alchemy_set_lpj(void);

+static bool alchemy_dma_coherent(void)
+{
+ switch (alchemy_get_cputype()) {
+ case ALCHEMY_CPU_AU1000:
+ case ALCHEMY_CPU_AU1500:
+ case ALCHEMY_CPU_AU1100:
+ return false;
+ case ALCHEMY_CPU_AU1200:
+ /* Au1200 AB USB does not support coherent memory */
+ if ((read_c0_prid() & PRID_REV_MASK) == 0)
+ return false;
+ return true;
+ default:
+ return true;
+ }
+}
+
void __init plat_mem_setup(void)
{
alchemy_set_lpj();
@@ -48,20 +65,8 @@ void __init plat_mem_setup(void)
/* Clear to obtain best system bus performance */
clear_c0_config(1 << 19); /* Clear Config[OD] */

- hw_coherentio = 0;
- coherentio = IO_COHERENCE_ENABLED;
- switch (alchemy_get_cputype()) {
- case ALCHEMY_CPU_AU1000:
- case ALCHEMY_CPU_AU1500:
- case ALCHEMY_CPU_AU1100:
- coherentio = IO_COHERENCE_DISABLED;
- break;
- case ALCHEMY_CPU_AU1200:
- /* Au1200 AB USB does not support coherent memory */
- if (0 == (read_c0_prid() & PRID_REV_MASK))
- coherentio = IO_COHERENCE_DISABLED;
- break;
- }
+ coherentio = alchemy_dma_coherent() ?
+ IO_COHERENCE_ENABLED : IO_COHERENCE_DISABLED;

board_setup(); /* board specific setup */

--
2.29.2